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Abstract #20 — A quantitative analysis of strain following post placement
Journal of Endodontics
AAE Abstracts of Papers
A B S T R A C T #21 - The validity of pulp vitality testing with the laser doppler. J.M. Musselwhite* University of North Carolina, Chapel Hill, North Carolina Objective: The purpose of this investigation was to establish the validity of a new generation of laser doppler flowmeters (LDF) for detecting blood flow in the coronal pulps of anterior teeth. Methods: Two laser doppler flowmeters, the advance laser flowmeter ALF 21 and the BPM2 were used on the maxillary incisors of sixteen volunteer subjects. Each patient was connected to an electrocardiograph and simultaneous records were made of the subject's pulse and the flow readings produced by each machine. Each subject was then injected with lidocaine with epinephrine and recordings were again made with each LDF. Results and Conclusions: Preliminary results indicate a constant, synchronized relationship between the patient's cardiac rhythum and flow readings produced by each machine. This relationship along with the changes noted after injection of lidocaine seem to confirm the validity of these new instruments as indicators of blood flow in the pulp tissue. Supporting Institutions: Research and Education Foundation of the AAE, University of North Carolina.
R e s e a r c h S e m i n a r III Friday, May 8, 9:00 - 12 noon Graduate Student Section A B S T R A C T #19 - Lingual infiltration and combination IAN/ Infiltrations in mandibular anterior anesthesia. K.C. Clark*, A. Reader, W. Meyers, M. Beck, R. Nist Ohio State University, Columbus, Ohio The purpose of this study was to measure the degree of anesthesia obtained with a lingual infiltration, and a combination inferior alveolar nerve block plus either a labial or lingual infiltration in the mandibular lateral incisor. Using a repeated measures design, 40 subjects randomly received four sets of the three injection combinations at four successive appointments: 1.IAN (mock) + Lingual (1.8ml) + Labial (mock); 2. IAN (3.6ml) + Lingual (mock) + Labial (mock); 3. IAN (3.6ml) + Labial (mock) + Lingual (1.8ml); 4. IAN (3.6ml) + Lingual (mock) + Labial (1.8ml). The anesthetic solution was 2% lidocaine with 1:100,000 epinephrine. The mock injections (no solution deposition) effectively blinded the subjects to the injections used. The lateral incisor was the site of injection for the infiltrations. At each of the four appointments, the lateral incisor, adjacent central incisor and canine, and contralateral canine (+ & - controls) were blindly tested with an Analytic Technology pulp tester at two minute cycles for 60 minutes. Anesthetic success was defined as no subject response to the maximum output of the pulptester (80 reading) within 15 minutes (IAN), or within 8 minutes (infiltration), and maintenanceof this reading for 60 minutes. Statistical analysis was performed with McNemar tests. For the lateral incisor, the anesthetic success rates were: 8% for the lingual infiltration; 40%forthe IAN; 60% forthe IAN/lingualinfiltration; and 63% for the IAN/labial infiltration. We concluded that the lingual infiltration is ineffective as a primary anesthetic technique. A labial or lingual infiltration could be added to the inferior alveolar nerve block to increase anesthetic success.
A B S T R A C T #22 - Effects of experimental evoked pai.n on pulpal pain. A. Sigurdsson*, W. Maixner University of North Carolina, Chapel Hill, North Carolina Historically, counterirritation has been used therapeuticallyto relieve pain of various origins. The underlying mechanisms which contribute to this effect are poorly understood, especially for pain arising from pulpal tissue. The objective of this study was to assess: 1) whether experimentally administered noxious stimuli alters and/or relieves pulpal pain; and 2) whether pain of pulpal origin is associated with an alternation in experimental pain perception. Ten adult males experiencing acute pulpitis rated the intensity and unpleasantness of their pain using validatedscales. The patients also outlinedthe spatial distribution of their facial pain on a figurine. Experimental pain threshold and tolerance were established with a thermode and by a tourniquet procedure. At the time of arm ischemic pain tolerance, all participants reported significantly less pulpal pain. The spatial pain distribution was also dramatically reduced to either nothing or to a point source localizedto the tooth producing the pain. The pulpal pain was still significantly less five minutes after the tourniquet procedure while the arm was pain free. The experimental protocol was repeated one week later on six patients. The threshold and tolerance values were not significantly different between the two experimentalsessions. Supported by the Research and Education Foundation of the AAE.
A B S T R A C T #20 - A quantitative analysis of strain following post placement. S.R. Sheldon*, J.G. Cailleteau University of Texas Houston Health Science Center Dental Branch, Houston, Texas Posts are frequently recommended for restorative procedures following endodontic therapy. The purpose of this study was to investigate the change in strain occurring near the apical end of a post placed within the root of a maxillaryanterior tooth. Strain gages were bonded to the apical third of the lingual root surface of 14 intact, freshly extracted, human anterior teeth positioned in an acrylic socket lined with poly(methylmethacrylate). Polyvinylsiloxane was used to simulate a PDL. Strains resulting from the cyclic application of a maximum force of 111 N, applied at a rate of 37 N/s, and directed at 110° to the longitudinal axis on the lingual aspect of the crown were recorded for three conditions using paired samples: (1) intact tooth, (2) after endodontic treatment, and (3) after restoration using a Parapost PlusTM. Two sets of ten load cycles were applied. Statistical analysis was performed using the Kruskal-Wallis 1-WAY ANOVA. As illustrated in the table below, when the gage was bonded coronal to the apical end of the post (5 teeth) there was significantly less strain after post placement. In contrast, when the gage was bonded apical to the post apex (9 teeth) there was significantly greater strain after post placement. Average strain is shown below in dimensionless units. Intact Gage coronal to Post Apex 1129 Gage apical to Post Apex 1073 * Indicates a significant difference
Endo 1202 1109
A B S T R A C T #23 - Identification of a psychosocial model as a predictor of flare-ups. A.S. Law*, H.L. Logan, R.E. Walton University of Iowa, Iowa City, Iowa A patient's self-reported pre-appointment pain level has been associated with increased likelihood of flareups (interappointment pain and/or swelling requiring an unscheduled visit). The purpose of this study was to extend prior findings by using discriminant analysis to identify a combination of psychosocial factors which would predict whether a patient would have a flare-upfollowing a RCT appointment. This study combined information obtained as part of two concurrent projects conducted in the College of Dentistry clinics. In the first study, psychosocial variables such as levels of pre-appointment pain and distress as well as levels of pain, distress, and control patients expected and experienced as a result of RCT were collected. In the second study treatment data such as signs, symptoms, treatment performed, and incidence of post operative appointments were collected. Patients having both psychosocial variables and treatment information availablewere matched as to age and sex in two groups: flare-up and no-flare-up. Using discriminant analysis, a combination of psychosocial variableswere identified which correctly classified 79% of the patients
PQ~t 965* 1264*
The results indicate that strain in the root section apical to the post is increased as a consequence of post placement, which correlates well withpreviouslyreportedresultsusingtheFiniteElementMethod. This study also illustrates the abrupt change in the strain magnitude occurring near the apex of a post.
192
AAE Abstracts of Papers
A B S T R A C T #21 - The validity of pulp vitality testing with the laser doppler. J.M. Musselwhite* University of North Carolina, Chapel Hill, North Carolina Objective: The purpose of this investigation was to establish the validity of a new generation of laser doppler flowmeters (LDF) for detecting blood flow in the coronal pulps of anterior teeth. Methods: Two laser doppler flowmeters, the advance laser flowmeter ALF 21 and the BPM2 were used on the maxillary incisors of sixteen volunteer subjects. Each patient was connected to an electrocardiograph and simultaneous records were made of the subject's pulse and the flow readings produced by each machine. Each subject was then injected with lidocaine with epinephrine and recordings were again made with each LDF. Results and Conclusions: Preliminary results indicate a constant, synchronized relationship between the patient's cardiac rhythum and flow readings produced by each machine. This relationship along with the changes noted after injection of lidocaine seem to confirm the validity of these new instruments as indicators of blood flow in the pulp tissue. Supporting Institutions: Research and Education Foundation of the AAE, University of North Carolina.
R e s e a r c h S e m i n a r III Friday, May 8, 9:00 - 12 noon Graduate Student Section A B S T R A C T #19 - Lingual infiltration and combination IAN/ Infiltrations in mandibular anterior anesthesia. K.C. Clark*, A. Reader, W. Meyers, M. Beck, R. Nist Ohio State University, Columbus, Ohio The purpose of this study was to measure the degree of anesthesia obtained with a lingual infiltration, and a combination inferior alveolar nerve block plus either a labial or lingual infiltration in the mandibular lateral incisor. Using a repeated measures design, 40 subjects randomly received four sets of the three injection combinations at four successive appointments: 1.IAN (mock) + Lingual (1.8ml) + Labial (mock); 2. IAN (3.6ml) + Lingual (mock) + Labial (mock); 3. IAN (3.6ml) + Labial (mock) + Lingual (1.8ml); 4. IAN (3.6ml) + Lingual (mock) + Labial (1.8ml). The anesthetic solution was 2% lidocaine with 1:100,000 epinephrine. The mock injections (no solution deposition) effectively blinded the subjects to the injections used. The lateral incisor was the site of injection for the infiltrations. At each of the four appointments, the lateral incisor, adjacent central incisor and canine, and contralateral canine (+ & - controls) were blindly tested with an Analytic Technology pulp tester at two minute cycles for 60 minutes. Anesthetic success was defined as no subject response to the maximum output of the pulptester (80 reading) within 15 minutes (IAN), or within 8 minutes (infiltration), and maintenanceof this reading for 60 minutes. Statistical analysis was performed with McNemar tests. For the lateral incisor, the anesthetic success rates were: 8% for the lingual infiltration; 40%forthe IAN; 60% forthe IAN/lingualinfiltration; and 63% for the IAN/labial infiltration. We concluded that the lingual infiltration is ineffective as a primary anesthetic technique. A labial or lingual infiltration could be added to the inferior alveolar nerve block to increase anesthetic success.
A B S T R A C T #22 - Effects of experimental evoked pai.n on pulpal pain. A. Sigurdsson*, W. Maixner University of North Carolina, Chapel Hill, North Carolina Historically, counterirritation has been used therapeuticallyto relieve pain of various origins. The underlying mechanisms which contribute to this effect are poorly understood, especially for pain arising from pulpal tissue. The objective of this study was to assess: 1) whether experimentally administered noxious stimuli alters and/or relieves pulpal pain; and 2) whether pain of pulpal origin is associated with an alternation in experimental pain perception. Ten adult males experiencing acute pulpitis rated the intensity and unpleasantness of their pain using validatedscales. The patients also outlinedthe spatial distribution of their facial pain on a figurine. Experimental pain threshold and tolerance were established with a thermode and by a tourniquet procedure. At the time of arm ischemic pain tolerance, all participants reported significantly less pulpal pain. The spatial pain distribution was also dramatically reduced to either nothing or to a point source localizedto the tooth producing the pain. The pulpal pain was still significantly less five minutes after the tourniquet procedure while the arm was pain free. The experimental protocol was repeated one week later on six patients. The threshold and tolerance values were not significantly different between the two experimentalsessions. Supported by the Research and Education Foundation of the AAE.
A B S T R A C T #20 - A quantitative analysis of strain following post placement. S.R. Sheldon*, J.G. Cailleteau University of Texas Houston Health Science Center Dental Branch, Houston, Texas Posts are frequently recommended for restorative procedures following endodontic therapy. The purpose of this study was to investigate the change in strain occurring near the apical end of a post placed within the root of a maxillaryanterior tooth. Strain gages were bonded to the apical third of the lingual root surface of 14 intact, freshly extracted, human anterior teeth positioned in an acrylic socket lined with poly(methylmethacrylate). Polyvinylsiloxane was used to simulate a PDL. Strains resulting from the cyclic application of a maximum force of 111 N, applied at a rate of 37 N/s, and directed at 110° to the longitudinal axis on the lingual aspect of the crown were recorded for three conditions using paired samples: (1) intact tooth, (2) after endodontic treatment, and (3) after restoration using a Parapost PlusTM. Two sets of ten load cycles were applied. Statistical analysis was performed using the Kruskal-Wallis 1-WAY ANOVA. As illustrated in the table below, when the gage was bonded coronal to the apical end of the post (5 teeth) there was significantly less strain after post placement. In contrast, when the gage was bonded apical to the post apex (9 teeth) there was significantly greater strain after post placement. Average strain is shown below in dimensionless units. Intact Gage coronal to Post Apex 1129 Gage apical to Post Apex 1073 * Indicates a significant difference
Endo 1202 1109
A B S T R A C T #23 - Identification of a psychosocial model as a predictor of flare-ups. A.S. Law*, H.L. Logan, R.E. Walton University of Iowa, Iowa City, Iowa A patient's self-reported pre-appointment pain level has been associated with increased likelihood of flareups (interappointment pain and/or swelling requiring an unscheduled visit). The purpose of this study was to extend prior findings by using discriminant analysis to identify a combination of psychosocial factors which would predict whether a patient would have a flare-upfollowing a RCT appointment. This study combined information obtained as part of two concurrent projects conducted in the College of Dentistry clinics. In the first study, psychosocial variables such as levels of pre-appointment pain and distress as well as levels of pain, distress, and control patients expected and experienced as a result of RCT were collected. In the second study treatment data such as signs, symptoms, treatment performed, and incidence of post operative appointments were collected. Patients having both psychosocial variables and treatment information availablewere matched as to age and sex in two groups: flare-up and no-flare-up. Using discriminant analysis, a combination of psychosocial variableswere identified which correctly classified 79% of the patients
PQ~t 965* 1264*
The results indicate that strain in the root section apical to the post is increased as a consequence of post placement, which correlates well withpreviouslyreportedresultsusingtheFiniteElementMethod. This study also illustrates the abrupt change in the strain magnitude occurring near the apex of a post.
192